How can you tell if she's going to be a nightmare?

[Teal Lantern]

I've read a few horror stories about women who were / seemed great to begin with, but then further down the line (including but not limited to after having kids or getting married or living together), they changed, in a negative way. Or their true colours came out.

What are the signs? How can you tell if she's going to be a nightmare years down the line?

There must be signs. Does anyone know? Does anyone have any links to this kind of information?

I know that people naturally change a bit over time or due to circumstances etc, and that's fine, that can be dealt with. But what I'd like to be able to do is avoid deception.

How about these for signs of mental illness?
http://www.foxnews.com/health/2012/11/2 ... etter-fit/
http://www.dailymail.co.uk/health/artic ... y-NHS.html